Domestic oven burners and control means



Jan. 30, 1968 T. P. FLEER 3,366,329

DOMESTIC OVEN BURNERS AND'CONTROL MEANS Filed oct. 22, 1965 United States Patent O 3,366,329 DOMESTIC OVEN BURNERS AND CONTROL MEANS Thomas I. Fleer, Sunset Hills, Mo. (29 Black Ciak Drive, St. Louis, Mo. 63127) Fiied Get. 22, 1965, Ser. No. 501,182 Claims. (Cl. 236-15) This invention relates to domestic cooking oven burners and control means therefor, and particularly to a simple and economical arrangement by which the range of oven temperatures which may be obtained is extended to include lower temperatures than may be practically or safely obtained with a single main burner.

An object of the invention is to provide in a domestic cooking oven a main burner, a pilot burner, and automatic control means for these burners which when adjustably positioned in the high range of its adjustment operates and regulates the output of the main burner to heat and maintain selected oven temperatures through a relatively high temperature range and simultaneously operates the pilot lburner at a xed, relatively low output as a stand-by igniter, and when adjustably positioned in the low range of its adjustment operates the pilot burner alone at some higher output as required to heat and maintain selected oven temperatures in a relatively low temperature range.

Further objects and advantages will appear from the following description and accompanying drawing.

In the drawing:

FIG. l is a longitudinal cross-sectional view of a gas burner control device constructed in accordance with the present invent-ion shown schematically associated with a main and a pilot burner arranged in an oven;

FIG. 2 is a top plan view of the adjustment knob and indicia plate of the control device shown in FIG. l;

FIG. 3 is a cross-sectional View taken on line 3-3 of the control device shown in FIG. 1;

FIGS. 4, 4A, and 4B are cross-sectional views taken on line 4 4 of the control device of FIG. l, showing different operative positions; and

FIGS. 5 and 5A are cross-sectional views taken on line 5-5 of FIG. l, showing different operative positions.

VReferring to the drawing, a main burner indicated at 1Q and a pilot burner indicated at 12 are shown arranged in an oven 14 indicated by a dot-dash line enclosure. The pilot burner 12 is positioned in igniting relationship with main burner 10. Gas is supplied to the main and pilot burners I@ and 12, as required, through a burner control device generally indicated at 16. The control device 16 comprises a main body member 13 having an inlet 26 to be connected to a supply source and a lower flange member 22 having main and pilot fuel outlets 24 and 26 connected, respectively, to the main burner and pilot burner 12 by suitable conduit means. The control device 16 further includes an upper cap member 28. The lower ange member 22 and upper cap member 28 are attached to the main body member 13 by any suitable means such as screws.

The main body member 1 has a lower cylindrical bore 3i?, an intermediate cylindrical bore 32 of slightly smaller diameter extending upwardly :from bore 30, and an upwardly ared tapered bore 34 extending upward-ly from intermediate bore 32 to the upper end of main body casting 18. The intermediate bore 32 is provided with screw threads and receives in threaded engagement an externally threaded, hollow, cylindrical valve seat member 36. The lower end of valve seat member 36 extends into lower cylindrical bore 39 and is provided at its lower end with a valve seat 3S which cooperates with a disc valve 4Q'.

A hollow, tapered, rotary plug valve 42 is fitted into the upper tapered bore 34 and is rmly retained in seated ICC position therein by a spring 44 biased between the upper end of plug valve 42 and the cap member 28. The plug valve 42 has an upwardly extending hollow stem 46 which extends through and is journalled in a bore in body cap member 28. The exterior projecting end of stem 46 iS provided with a knob d8 rigidly attached thereto.

The hollow, cylindrical, valve seat member 36 is provided with an intermediate transverse wall 50 from which extends both upwardly and downwardly a concentric axial stem S2. The stem 52 extends upwardly from wall 59 through the hollow plug valve stem i6 to the knob 48 to which it is rigidly connected so that the stem 52, as well as hollow -stem 46, rotates with knob 48. That portion of stem 52 extending downwardly from transverse Wall 5t) is hollow, forming a Huid passageway 54, and a seat 56 is formed at the lower end thereof for cooperation with a valve 58 attached to and movable with disc valve 40. The intermediate transverse wall 5t) is provided with a plurality of perforations di) to permit free passage of fluid through hollow valve seat member 36, and the wall 50 is further provided with a transverse passage 62 which intersects and forms a continuation of passageway 54.

The disc valve 4G is provided with a downwardly directed axial stem and follower 6ft, the end of which bears against the iiexible wall 66 of an expansible chamber. The expansible chamber further comprises a rigid, cupshaped member 68. The cup 63 has an axial, downwardly extending, hollow, threaded boss '79 which passes through a bore in lower flange member 22 and receives a nut 72. A sensing bulb 74, positioned in the oven 14 so as to sense the temperature therein, is connected to the expansible chamber by a capillary tube 76. The expansible chamber, capillary tube 76, and bulb 74 form a sealed system filled with a thermally expansible liquid. A return spring 78 biases valve 4d against the movable wall 66 of the expansible chamber and biases the movable wall toward a contracted position.

The hollow plug valve 42 is provided with a lateral port S9 aligned with inlet 26 and an exterior groove 82 also aligned with inlet 20 and extending part way around the periphery of the plug valve so as to provide communication between inlet 2G and the interior of hollow plug valve 42 through a range of rotatably adjusted positions, see FIGS. 4, 4A, and 4B. The groove l82 comprehends a sutiicient portion of the periphery of the plug valve 42 to provide communication between its interior and inlet 20 through a wide range of rotation of the plug valve as indicated in FIGS. 4 and 4A, the communication being cut off only when the valve is rotated to the position shown in FIG. 4B.

The plug valve 42 is further provided with a cam surface which takes the form of a peripheral groove 84 in the exterior surface of the plug valve. The groove 84 is aligned with a follower pin S6 which bears at one end against a normally closed, spring-pressed, ball valve 83 and against the surface of the plug valve at its other end. The ball valve 88 controls communication between the lower cylindrical bore Sti and the main outlet 24 via passages 90 and 92. A branch comprising passageways 94, 96, and 98 also provides communication between outlet 24 and intermediate bore 32 via passage 92. This branch passage is controlled by threadedly adjustable needie valve 10Q.

Communication between intermediate bore 32 and pilot outlet 26 is provided by passageways 162, 1634, idd, and 108. Passage N2 is under control of a threadedly adjustable needle valve 110. Communication is also provided between intermediate bore 32 and pilot outlet 2e via passages 54, 62, 106, and 16S. This communication is under the control of a threadedly adjustable needle valve 112 in passage 106.

Operation In FIG. 2 of the drawing, the knob 48 is shown in a position, as indicated by the arrow on knob 48, at the upper limit of a low temperature range, extending, for example, from l25 Fahrenheit to 250 Fahrenheit. When the knob is in this position, the plug valve 42 will be in the position shown in FIGS. 4 and 5. That is, inlet 20 will be in communication with pilot outlet 26 via hollow plug valve 42, the intermediate bore 32, and passages 102, 104, and 108 to supply a fixed amount of gas, as determined by adjustment of needle valve 110, sufdcient only for ignition of pilot burner 12. In this position, the normally closed, spring-pressed valve 8S will be closed, due to the fact that follower pin S6 is resting in groove 84, so that no ilow to the main burner through passage 92 can occur. When with the plug valve in this position the oven temperature falls below 250 Fahrenheit, the liquid in sensing bulb 70 will contract and valves 4t) and 58 will move slightly openward. rhe opening of valve 58 from its seat 55 will permit the additional required fuel to ow to pilot burner 12 to increase its output and restore the 250 Fahrenheit oven temperature.

The maximum amount of fuel which can flow to pilot burner 12 is determined by the adjustment of needle valve 112, and this amount would be that which is sufficient to provide an oven temperature of 250 Fahrenheit. If it is desired to maintain a lower oven temperature than 250 Fahrenheit, the knob 43 is rotated counterclockwise with reference to FIG. 2. This rotation of knob 48 causesl valve seat member 36 to be moved downward toward valve 58, thereby requiring the oven temperature to fall lower before valve S is opened. It is to be understood that the external threads on valve member 35 and the internal threads in bore 32 are left-hand. It will be noted that as valve 42 is rotated counterclockw-ise from the position shown in FIG. 4 closure of the inlet will progress until complete cutoff occurs in the position shown in FIG. 4B. Suflcient flow to provide that required to be supplied to the pilot burner will continue, however, until the plug valve has moved at least halfway from its FIG. 4 to FIG. 4B position.

When higher oven temperatures than 250 Fahrenheit are desired, the plug valve is rotated clockwise from the position shown in FIG. 2 to some position in the higher temperature range as indicated at 400 Fahrenheit, for example. In this position inlet 20 will be in communication with the interior of hollow plug valve 42 by reason of the groove S2, as shown in FIG. 4A, and ball valve S3 will be open because follower pin 86 is now riding on the ungrooved portion of the plug valve surface. Under these conditions a fixed minimum flow will be supplied to the main burner 10 through passages 92, 94, 96, and

by effecting opening of valve 40 at higher or lower oven temperatures The minimum flow to the main burner as determined by needle valve 100 is that which is consideredto be a safe turndown of the main burner. If the characteristics of the main burner are such that a safe turndown minimum heats the oven to a higher temperature than the 250 Fahrenheit indicated, then the needle valve 112 controlling the maximum flow to the pilot burner will need to the adjusted to increase the ow to the pilot burner. Under these conditions the upper limit of the low temperature range would be raised.

98, as determinedby adjustment of needle valve 100,

regardless of the position of valve 40. This fixedV minimum flow, together with the xed minimum flow to the pilot burner, will be sul'licient to maintain an oven temperature of at least 250 Fahrenheit when valves 40 and 'V58 are completely closed. The fixed minimum flow to the pilot burner is, however, substantially negligible; the function of the pilot burner under these conditions is to provide safety stand-by ignition means in the event the main burner is extinguished.

When the knob is set at some position above 250 Fahrenheit and the oven temperature falls below this setting, the valve 40 will move openward due to contraction of the liquid in bulb 74. This permits additional flow The foregoing description is intended to be illustrative and not limiting, the scope of the invention being set forth in the appended claims.

I claim:

1. In an oven heating system, a main burner, a pilot burner in igniting relationship with said main burner, a fuel control device having a chamber formed therein, said chamber having an inlet, a main burner outlet, and aV pilot burner outlet, means forming a valve seat at said inlet and at said main and pilot burner outlets, a manually operable valve cooperating with said inlet seat, a main burner proportioning valve cooperating with said main burner outlet seat and a pilot burner proportioning valve cooperating with said pilot burner outlet seat, a temperature responsive actuator responsive to the oven temperature operatively connected Lto said main and pilot burner proportioning valves and operative to move both valves simultaneously in the same direction as it responds to an oven temperature change, manual temperature adjustment means operative to vary the relative positions of said proportioning valves and their seats, thereby to vary the oven temperature which will be maintained asV a result of thermostatic actuation of said valves, means formingV main and pilot'burner fuel passageways leading from said main and pilot burner outlets to said main and pilot burners, a cutoff valve in said main burner passageway, said cutoff valve being operatively` connected to said manual temperature adjustment means and moved between open and closed positions respectively thereby as said manual temperature adjustment means is moved above and below a predetermined oven temperature setting, a branch fuel passageway connecting said chamber with said main burner fuel passageway at a point anterior to said cutoff valve and bypassing said main burner proportioning valve, and a branch fuel passageway connecting said chamber with said pilot burner passageway and bypassing said pilot burner proportioning valve, thereby to supply a predetermined flow to said main and pilot burners irrespective of the position of said proportioning valves.

2. An oven heating system as set forth in claim 1 in which manually adjustable valve means is interposed in said branch fuel passageway connecting said chamber with said main burner fuel passageway, whereby the predetermined flow to said main burner bypassing said proportioning valve means may be varied, and in which a manually adjustable Valve is interposed in said pilot burner fuel passageway whereby the maximum flow to the pilot burner under any conditions may be varied.

3. An oven heating system as set forth in claim 1 in which said main and pilot burneroutlets and their respective valve seats are formed concentric, in which said main and pilot burner proportioning valves cooperating with said seats are concentric discs, aud in which said main and pilot burner outlet valve seats are movable axially with respect to said proportioning valves.

4. In an oven burner control system in which fuel is supplied to both a main burner and a pilot burner at rates required to jointly maintain a higher range of selected oven temperatures and in which fuel is supplied as required to the pilot burner only to maintain by its sole operation a lower range of selected oven temperatures; a control device having a chamber arranged for connection to a source of uid fuel supply, a main and a pilot burner fuel passage leading from said chamber to a main burner and pilot burner, thermostatic proportioning valve means controlling the flow of fuel through both of said passages, and manual means for adjusting said thennostatic proportioning valve means, means providing a predetermined minimum flow of fuel to said main burner and to said pilot burner independent of the control of said proportioning valve means, a cutol valve controlling the flow through said main burner fuel passageway at a point therealong which effects the cutol of all fuel ow to the main burner, including said predetermined minimum flow when this valve is closed, and said manual means having an operative connection with said cutol valve and being operative to open said valve when said manual means is moved in one direction from a predetermined position when adjusting said thermostatic proportioning valve means and being operative to close said valve when it is moved in an opposite direction from said predetermined position when adjusting said thermostatic proportioning valve means.

5. In an oven control system as set forth in claim 4 in which said control device chamber includes an inlet, an inlet valve seat, and a rotary valve cooperating with said seat, which said rotary valve is ported so as to be open to admit fuel to said chamber during the greater part of one revolution and to be closed during only a small part thereof, and in which said manual means is operatively connected to said rotary valve.

References Cited UNITED STATES PATENTS 2,950,865 8/1960 Lamar 236--32 3,255,965 6/1966 Wilson 236--15 3,288,366 ll/l966 Fleer 236-15 EDWARD I. MICHAEL, Primary Examiner. 

4. IN AN OVEN BURNER CONTROL SYSTEM IN WHICH FUEL IS SUPPLIED TO BOTH A MAIN BURNER AND A PILOT BURNER AT RATES REQUIRED TO JOINTLY MAINTAIN A HIGHER RANGE OF SELECTED OVEN TEMPERTURES AND IN WHICH FUEL IS SUPPLIED AS REQUIRED TO THE PILOT BURNER ONLY TO MAINTAIN BY ITS SOLE OPERATION A LOWER RANGE OF SELECTED OVEN TEMPERATURES; A CONTROL DEVICE HAVING A CHAMBER ARRANGED FOR CONNECTION TO A SOURCE OF FLUID FUEL SUPPLY, A MAIN AND A PILOT BURNER FUEL PASSAGE LEADING FROM SAID CHAMBER TO A MAIN BURNER AND PILOT BURNER, THERMOSTATIC PROPORTIONING VALVE MEANS CONTROLLING THE FLOW OF FUEL THROUGH BOTH OF SAID PASSAGES, AND MANUAL MEANS FOR ADJUSTING SAID THERMOSTATIC PROPORTIONING VALVE MEANS, MEANS PROVIDING A PREDETERMINED MINIMUM FLOW OF FUEL TO SAID MAIN BURNER AND TO SAID PILOT BURNER INDEPENDENT OF THE CONTROL OF SAID PROPORTIONING VALVE MEANS, A CUTOFF VALVE CONTROLLING THE FLOW THROUGH SAID MAIN BURNER FUEL PASSAGEWAY AT A POINT THEREALONG WHICH EFFECTS THE CUTOFF OF ALL FUEL FLOW TO THE MAIN BURNER, INCLUDING SAID PREDETERMINED MINIMUM FLOW WHEN THIS VALVE IS CLOSED, AND SAID MANUAL MEANS HAVING AN OPERATIVE CONNECTION WITH SAID CUTOFF VALVE AND BEING OPERATIVE TO OPEN SAID VALVE WHEN SAID MANUAL MEANS IS MOVED IN ONE DIRECTION FROM A PREDETERMINED POSITION WHEN ADJUSTING SAID THERMOSTATIC PROPORTIONING VALVE MEANS AND BEING OPERATIVE TO CLOSE SAID VALVE WHEN IT IS MOVED IN AN OPPOSITE DIRECTION FROM SAID PREDETERMINED POSITION WHEN ADJUSTING SAID THERMOSTATIC PROPORTIONING VALVE MEANS. 